How long does a dep discharge generally take?

well, I'm going to ask to be dep discharged from the army national guard because I don't want to be in it anymore. I joined during the middle of my high school senior year. I just graduated from high school may 29. I just don't have the desire to be in it anymore. so, how long does it take for this to be processed? could I possibly join the military later on in life? how many times can you dep discharge before you're not allowed to join again? answers please!